39 lines
930 B
Go
39 lines
930 B
Go
package auth
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import (
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"crypto/rand"
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"crypto/sha256"
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"strings"
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"time"
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)
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const sessionExpiresInSeconds = 60 * 60 * 24 // 1 day
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func GenerateSecureRandomString() (string, error) {
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// Human readable alphabet (a-z, 0-9 without l, o, 0, 1 to avoid confusion)
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alphabet := "abcdefghijklmnpqrstuvwxyz23456789"
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// Generate 24 bytes = 192 bits of entropy.
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// We're only going to use 5 bits per byte so the total entropy will be 192 * 5 / 8 = 120 bits
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bytes := make([]byte, 24)
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_, err := rand.Read(bytes)
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if err != nil {
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return "", err
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}
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var id strings.Builder
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for _, b := range bytes {
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// >> 3 "removes" the right-most 3 bits of the byte
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id.WriteByte(alphabet[b>>3])
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}
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return id.String(), nil
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}
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func HashSecret(secret string) []byte {
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hash := sha256.Sum256([]byte(secret))
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return hash[:]
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}
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func CheckExpiration(expirarion time.Time) bool {
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return time.Since(expirarion).Seconds() >= sessionExpiresInSeconds
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}
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